A demonstration of Core Audio applied to Max Mathews' work on Radio Baton and Composer.

1. Creating Music
Instruments on iOS
Greg Cerveny
@gmcerveny
greg.cerveny@gmail.com
Tuesday, September 11, 12

2. Music on iOS
• Apple Design Award Apps
• DM 1, Djay, Tab Toolkit
• Companies: Smule, Tonara, Khush
• Great Apps: Figure, Lemur, Animoog, ...
• Apple Store
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3. Tuesday, September 11, 12

4. Tuesday, September 11, 12

5. Max Mathews Radio Baton Video Demo:
http://www.youtube.com/watch?
v=3ZOzUVD4oLg#t=4m46s
Tuesday, September 11, 12

6. Core Audio
• Audio and MIDI support
• Low Latency & Dynamic
• Objective C and C
• Proxy Objects
• Audio Toolbox, Audio Unit, Core MIDI
Frameworks
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7. Introduction to
Computer Music
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8. Introduction to
Computer Music
• Notes
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9. Introduction to
Computer Music
• Notes
• Signals
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10. Sonata No. 14, 'Moonlight'
Ludwig van Beethoven
Adagio sostenuto Op. 27, No. 2
Si deve suonare tutto questo pezzo delicatissimamente e senza sordini
3 5 2 4 3 5
1 3 1
sempre pianissimo e senza sordini 5
4 pp
5
2 3 5 4 5 3 5
4 3
1
4 5
4
5
7 5 4 3
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11. 1. Music File
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12. 2. Set Up Music Sequence
• Create a new music sequence
NewMusicSequence(MusicSequence *outSequence)
• Load a music file
MusicSequenceFileLoad(
MusicSequence inSequence,
CFURLRef inFileRef,
MusicSequenceFileTypeID inFileTypeHint,
MusicSequenceLoadFlags inFlags)
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13. 3. Load Into Music Player
• Create a new music player
NewMusicPlayer(MusicPlayer *outPlayer)
• Load sequence into player
MusicPlayerSetSequence(MusicPlayer inPlayer,
MusicSequence inSequence)
• Play
MusicPlayerStart(myMusicPlayer)
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14. DEMO
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15. Music Player Types
• MusicPlayer
• MusicEventIterator
• MusicSequence
• MusicTrack
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16. Notes
• MIDI Notes
MIDINoteMessage {
UInt8 channel;
UInt8 note;
UInt8 velocity;
UInt8 releaseVelocity;
Float32 duration; }
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17. Signal
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18. 8 Steps to an Audio Graph
1. Configure an Audio Session
2. Create an Audio Processing Graph
3. Create and Describe Audio Nodes for Each Unit
4. Open the Audio Processing Graph to Instantiate the Audio Units
5. Obtain Pointers and Configure Each Unit
6. Connect the Nodes
7. Initialize the Graph
8. Start the Audio
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19. 8 Steps to an Audio Graph
• Create an Audio Processing Graph
NewAUGraph(AUGraph *outGraph)
• Describe Audio Node
AudioComponentDescription {
componentType;
componentSubType;
componentManufacturer;
componentFlags;
componentFlagsMask;
}
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20. 8 Steps to an Audio Graph
• Add Node to Graph
AUGraphAddNode(
AUGraph inGraph,
AudioComponentDescription *inDescription,
AUNode *outNode )
• Open the graph
AUGraphOpen(AUGraph inGraph)
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21. 8 Steps to an Audio Graph
• Pointers to Nodes
AUGraphNodeInfo(
AUGraph inGraph,
AUNode inNode,
AudioComponentDescription *outDescription,
AudioUnit *outAudioUnit)
• Connect Nodes
AUGraphConnectNodeInput(
AUGraph inGraph,
AUNode inSourceNode,
UInt32 inSourceOutputNumber,
AUNode inDestNode,
UInt32 inDestInputNumber)
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22. 8 Steps to an Audio Graph
• Initialize Graph
AUGraphInitialize(!
AUGraph inGraph)
• Start Audio
AUGraphStart(AUGraph inGrap)
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23. DEMO
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24. Audio Graph
• Audio Graph
• Creation, Opening, and Starting
• Nodes and Descriptions
• Audio Units
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25. Resources
• Learning Core Audio by Adamson
• WWDC
• 2011: Music in iOS and Lion
• 2010: Audio Development for iOS1/2
• Core Audio Programming Guide
• Audio Unit Hosting/Programming Guide
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26. Other Libraries
• C Sound
• LibPD - Pure Data
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27. Creating Music
Instruments on iOS
Greg Cerveny
@gmcerveny
greg.cerveny@gmail.com
Tuesday, September 11, 12